package question150;

import java.util.LinkedList;

public class Solution {
    public int evalRPN(String[] tokens) {
        LinkedList<Integer> stack = new LinkedList<>();
        for (String string : tokens) {
            switch (string) {
                case "+":
                    stack.push(stack.pop() + stack.pop());
                    break;
                case "-":
                    stack.push(stack.pop() - stack.pop());
                    break;
                case "*":
                    stack.push(stack.pop() * stack.pop());
                    break;
                case "/":
                    Integer num1 = stack.pop();
                    Integer num2 = stack.pop();
                    stack.push(num2 / num1);
                    break;
                default:
                    stack.push(Integer.parseInt(string));
            }
        }
        return stack.pop();
    }
}
